Process of producing and separating certain substances.



v. M. WEAVER. PROCESS OF PRODUCING AND SEPARATING CERTAIN SUBSTANCES.

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APPLICATION FILED JAN. 7, 1915.

am 4 W V. M. WEAVER.

PROCESS OF PRODUCING AND SEPARATING CERTAIN SUBSTANCES.

APPLICATION FILED JAN. 7. 1915.

l ,300,2 05. Patented 8, 1919.

SSHEE EET i E WMWM W47 'HIIUPHELJE V. M. WEAVER.

PROCESS OF PROEJUCING AND SEPARATING CERTAIN SUBSTANCES.

APPLICATION FILED JAN. 7. 1915.

1,300,205. Patented Apr. 8,1919.

A/HHEEEEE Invenlmr":

' ViEIUF M-WEEVEF UNITED STATES PATENT orrrcn VIQZL'OR M. WEAVER, 0FHARRISBURG, PENNSYLVANIA, ASSIGNOR TO WEAVER 4 COMPANY, A CORPORATION OFWISCONSIN. V

rnocnss or rnonucme AND SEPARATING CERTAIN SUBSTANCES.

Specification of Letters Patent.

Patented Apr. 8,1919;

Original application filed August 22, 1914,:Se1ia1 No. 858,001. Dividedand this application filed January 7, 1915. Serial No. 919.

To all whom itx-may concern:

Be it known that I, Vision M. \VEAVER, a citizen of the United States.residing at Harrisburg, in-the county of Dauphin and State ofPennsylvania, have invented a certain new and usefulImprovement inProcesses of Producing and Separating Certain Substances, of which thefollowing is a full, clear, concise, and exact description, referencebeing had to the accompanying drawings, forming a part of thisspecification.

My invention relates to a process of producing and separating substancesof certain quality, and While it will appear to those skilled in the artthat my invention may be employed in the treatment of any substances,either compounds or mixtures having the proper chemical and physicalcharacteristics, my invention is concerned particularly with thetreatment of substances containing at leastone metal and oxygen and,

in its more specific aspects with the production and separation ofaluminum chlorid and silicon tetrachlorid, due to their specialproperties and those of the charge as pointed out in the more specificof the appended claims. I

The application is divisional from the application which resulte in myPatent Number 1,238,604 dated August 28, 1917, which is concerned with aprocess of winning desired substances from mixtures and compounds inwhich they appear and which, for example and in its more specificaspects, relates to the treatment of clay or some similar material inorderto secure the aluminum and the silicon therefrom. The claims in theparent application are drawn toward the process as' a whole, that is,for example, the claiming of the complete process beginning with clay orsome similar material, such as bauxite and the proper reagents andending with the recovery of the aluminum and. silicon in theirelementary states without limitation to the particular manner in whicheach of the steps is carried out, except where such particular mannerinfluences or is influenced by any or all of the other steps.

The present application has to do with the novel and advantageousmanner, according to my' invention, in which a plurality of substancesare prepared and sepato instruct those rated,'in its more specificaspect being concerned with the preparation of aluminum chlorid andsilicon tetrachlorid from clay or some similar material and properreagents and with the separation of these two chlorids. a I shall nowvproceed with a specific description of my invention as embodied in myprocess of producing separately aluminum chlorid and silicontetrachlorid from clay, and -I shall refer to and describe the variousparts of the apparatus and the vari ous stages in the process in detail,in order skilled in the art. According to my invention I break up theclay by the use of chlorin gas so as to produce simultaneously aluminumchlorid and silicon tetrachlorid, this action being carried onunderspecial restrictions and conditions,

as will later be more fully described. I then chlorinizing furnace takenon the plane of the line 3-3 of Fig. 2 and looking in the directionindicated by the arrows.

Referring first to Fig. 1, it will be seen that the chlorinizing furnaceis shown at 9, and by reference 'to Figs. 2 and 3 it will be seen thatthis chlorinizing furnace is of the closed typeand provides for a bed ofcoke 10, in which a plurality of electrodes 111l, extending inwardlythrough the circular housing, as illustrated in Fig. 3, are lodged. Eachof thecarbon electrodes 11 is firmly mountedin a terra cotta .pipe 12,which in turn is mounted in the fire brick housing 13. An electricconductor 14 is provided for each of the carbon electrodes and thisconductor is in the form of a pipe which is connected with the electrodeat 15 and which is supported in position by means of a union 16 packedat 17. The pipe 14 is kept cool by a flow of water introduced throughthe entry pipe 18, and, after circulation, passed through the returnpipe 19. The usual insulated electric conductor may be attached to theend of the pipe 14, as illustrated, and at this distance from thefurnace will .not be injuriously aifected by the heat. The referencecharacter 21 indicates a cleanoutdoor which may be provided, and a peephole arrangement 22 may also be provided.

The charge is introduced into the chlorinizing furnace by way of a screwconveyer,

indicated at 23 at the bottom of a hopper bin 24-, this screw conveyerleading the charge to the passage 25, through which the charge may dropon to the bed of coke which has already been referred to.

The charge is indicated at 26 and the bed is preferably so arranged thatthe coke ex-' posed in the middle is surrounded by packed .clay,asillustrated at 27, 27. The charge may be any clay but I havefound thatthe higher grades of clay, such as kaolin, of the formula Al (SiO;,)(the moisture being driven therefrom) is especially. desirable. It willbe noted that the furnace has only the outlet 28 and it will be noted,as this description proceeds that the entire system is closed as thisfurnace is. It will be noted that a graphite pipe 29 extends through thefire brick housing of the furnace and terminates in the heart ofthe'coke bed. This pipe 29 is fed through a pipe 30 (Fig. 1)

from a storage tank 31, the connection being.

controlled by a; valve 32'. It will now be noted that with the chlorinproperly fed to the graphite pipe and with the current properly appliedto the electrodes the activity of the chlorin gas and the heatimmediately efiects the disintegration of the kaolin, the formation ofaluminum chlorid and silicon tetrachlorid, and, by the combination ofthe carbon and the oxygen liber-' ated from the kaolin, the formatlon ofcarbon monoxid. So far as the degree of heat is concerned, those skilledin the art will, of course, be guided by the fact that such a degree ofheat as effects reaction between the chlorin and the aluminum andsilicon is required, the efl'ective temperatures being well known in the'art.. I might add, forwhat further assistance it may give, that I havefound that temperatures between 900 and 1200 centigrade are mostefiicient.

The reaction is as follows:

the form of a double closed chamber providthe compartment 34 and thecompartment 35 separated by a partition 36. The

chamber and which are distributed throughhousing the conductor and itsinsulation out the entire space of this particular compartment in order.to get complete temperature control. The pipes 37, 37 are joined at theupper ends outside of the chamber .by means of the header pipe 38 andcirculation is secured in any deslrable manner. In this particularcondenser element the system of pipes is connected to a cold watersupply and the result is that as the three gases which have beenreferred to enter and pass through the-compartment 34 the aluminumchlorid gas, which condenses at a higher temperature than the silicontetrachlorid gas, is condensed and deposits itself as a white powderupon the pipes 37, 37. It might be mentioned here that it is possiblethat in the action in the chlorinizing furnace some other chlorid ofsilicon might incidentally be formed, a chlorid such as hexachlorid (SiCl but I find that conditions are such that it is only the silicontetrachlorid which plays any considerable part.

Since the temperature which is produced by the circulation of mere coldwater in the cooling pipes 37 37 is not sufficiently low to condensesilicon tetrachlorid, this gas, togetherwith the carbon monoxid, passeson to the next compartment 35 of the condenser. Thus the first condenserelement 34 is devoted to the condensation of the aluminum chlorid andthe white powder to which it is reduced is removed froln the pipes uponwhich it is deposited by means of the scrapers 39, 39, which by;means ofpulley cords the condenser element where the outlet 44 leading to a tank45 is provided. This out-- let may be controlled by a valve 46. It willbe noted that this tank is connected by means of a pipe 47 with acompressed air tank 48, which is fed through the air compressor 49. Itis important, as before indicated, that the system be a closed systemand that various actions be carried on under pressure, and I speak of itparticularly at this time because of the fact that the aluminum chloridto which I have just referred is extremely deliquescent and must'be keptfree from moisture in order to avoid decomposition and the formation ofhydrochloric acid. When the system is closed, however, such a result isnot possible, and the pressure has a purpose to be referred to later.

Leaving the aluminum chlorid, which has been deposited in the tank 45,for the present, it shall follow the course of the silicon tetrachloridgas and the carbon monoxid through the second element of the condenser.

The condenser element 35 is provided with less liquid, except for anyimpurities whichmay discolor it. This liquid silicon .tetrachloridpasses down the sloping bottom of the condenser element 35 and passesthrough the outlet 55. lhe condenser element 35 is provided withscrapers asthe condenser eletill ment 34 is, because it is possible thatthe aluminum chlorid not entirely condensed in its passage through thecondenser element 34 may condense upon the pipes 50 of the condenserelement 35,. and it is therefore desirable to periodically operate thescrapers 52 in order to remove this condensation. The scrapers 39 of theother condenser element are operated during all the time'that the systemis being worked. The condenser element 35 is provided with a conveyor58.

The carbon monoxid passes out of the condenser element 35 through a pipe59, past a valve and to a closed gas pump 61, and is then. carried to ascrubber 62 by means of. a pipe 63, this scrubber being in the form of atank containing lime water and having an outlet pipe 63 leadingtherefrom. This outlet pipe is provided with a valve 64 and leads to atelescoping gas tank 55's0 that pressure may be kept upon the carbonmonoxid whichv findsits way to this tank and so that the carbon monoxidmay be fed by way of a pipe 66 to a burner 67 which is used for heatingthe tank 45 for a purpose to which I shall now refer.

Returning now to the aluminum chlorid condenser deposited in the form ofa powder in the tank 45 (this powder being white unless discolored byimpurities), it will be noted that I have placed the burner 67 underthis tank, and I may mention he1;e that l surround the tank in practicewith a suit able fire wall, so that I can subject the tank to a highdegree of heat. With the valve 46 closed, the material in the tank 45can be placed under high pressure from the tank 48, and this pressure,together with the heat from the carbonmonoxid burner melts the" aluminumchlorid, after which step the aluminum chlorid is much more stable andmuch more easily handled,'due to its physical condition. I desire tostate, however, that it is entirely feasible to care for the aluminumchlorid in its powder condition.

A pipe 70 leads from the tank 45 to a valve 71; which in turn isconnected with a pipe 72 leading into a furnace, preferably of theltodenhauser three-phase type. lhis furnace comprises a heavy outerhousing 73, which is provided with a round bottom 74 mounted in acorrespondingly shaped base 75, the idea being that when the connectingpipes are temporarily detached the fur nace can be tilted in order totap off molten metal, as will be pointed out a little later. 'lhefurnaceprovides a cavity, for the molten metal.

The details'of this'furnace do not constitute part of mypresentinvention, but i I refer to them because it is a type of fur nacewell adapted for use as part of my systern. It wilLbe seen that when thevalve 71 is opened the liquid aluminum chlorid is conducted to theworking chamber of the lilodenhauser furnace. The reason for this stepin the process is as follows:

In the first condensation of the aluminum chlorid in the condenserelement 34 there are likely to be impurities, principally iron, \and itis the object of the step in the proc ess'now under description toeliminate this iron and to secure pure aluminum chlorid. Therefore,preliminarily, the Rodenhauser furnace is charged with aluminum and themolten bath, as illustrated, is formed, when, as before stated, thevalve 71 is openedand the liquid aluminum chlorid is fed into this bathof molten aluminum near the bottom thereof, the aluminum chlorid isimmediately reoonverted into a gas due to the release of pressure andheat of bath and passes up through the molten aluminum. Due to thegreater afinity of the chlorin for the aluminum than for the iron, orother. im-

purity for that matter, thechlorid releases the 1ron andv takes on theproper share of its aluminum. The result is that the refined.

aluminum 'chlorid will leave the bath of aluminum andwill pass out ofthe furnace through the pipe 81 and pipe 83 back to the condenser, whereit will be returned to its powder condition. The three-way valve 85 maybe provided so that if desired the purified aluminum chlorid may be ledto a separate condenser, so that the first condenser may operatecontinuously and without the introduction of purified aluminum chloridgas. It will also appear that if some of the silicon tetrachlorid shouldhappen to become condensed in the aluminum chlorid part of the condensersystem, such condensed silicon tetrachlorid will be removed with theimpurities in the Rodenhauser furnace since the aluminum has greaterafinity for chlorin than silicon and. the chloriuwi-ltrelease thesilicon and take up the proportionate share of aluminum, leaving thesilicon to be tapped off with the impurities.

It will be seen that the system is a closed system and that moisture iseffectively excluded so as to protect the active chlorids, particularlythe aluminum chlorids.

In charging the chlorinizing furnace 'it is good practice to mixcalcined clay and coke breeze to the right proportions before feeding itto the furnace and to drop the mixture through the roof. I also use a.deep fire and run the pile at a white heat.-

I desire to call attention to the fact that it is possible to treat theclay with chlorin in some other way than to feed the chlorin gas to thechlorinizing furnace, as has been described. I contemplate the use ofcompounds of chlorin to secure reactions, in or der to produce thechlorids. For instance, I might use carbon tetrachlorid (which may beproduced by passing chlorin through a glowing bed of coke) and feed thiscarbon tetrachlorid, which is a colorless mobile liquid, into thechlorinizing furnace with the clay or carbon, or'into the mixture ofclay and carbon already fed into the furnace.

I claim as new and desire to secure by Letters Patent: 1

1. The process of separating aluminum chlorid and silicon tetrachloridwhich comprises submitting the mixture to a moisture free atmospherewhich will condense the former but not the latter.

2. The process of separating aluminum chlorid and silicon tetrachloridwhich comprises submitting the mixture to a temperature above thefreezing point-of water to con dense the aluminum chlorid and thensubmitting the remaining gas to the freezing temperature of water tocondense the silicon tetrachlorid.

in a moisture free atmosphere to form aluminum chlorid, silicontetrachlorid and carbon monoxid, and then separating the two chlorids bya difference in temperature.

4. The process of treating clay with chlorin in a moisture freeatmosphere to form aluminum chlorid and silicon tetrachlorid,

- and thenseparating the two chlorids by a difference in temperaturep 5.The process of treating'clay with chlorin in amoisture free atmosphereto form aluminum chlorid and silicon tetrachlorid,

carbon to ,form aluminum chlorid, silicon tetrachlorid and carbonmonoxid, and then separating the two chlorids by a difference intemperature.

7. The process which comprises treating a substance containing aluminumand silicon with chlorin to form aluminum chlorid and silicontetrachlorid, and then separating the two chlorids in a moisture freeatmosphere by a difference of temperature.

8. The process which comprises treating a substance containing aluminumand silicon with chlorin in a moisture free atmosphere to form aluminumchlorid and silicon tetrachlorid, and then separating the two chloridsin a moisture free atmosphere by a difference of temperature.

9. The process which comprises treating a substance containing siliconwith a halogen to form a compound between the halogen and the silicon,and then condensing the gaseous compound thus formed in a mois= turefree atmosphere.

10. The process which comprises treating clay with chlorin in thepresence of a reducing agent and in a moisture free atmosphere to formaluminum chlorid, silicon tetrachlorid and a compound of said reducingagent and oxygen, and then separating the two chlorids by a differencein temperature.

11. The process which comprises treating a continuously fed charge witha continuously fed' gas to form continuously a mixture of gaseouscompounds, and then separating said gaseous compounds byfractional'condensation at the same rate at which they are formed.

12. The process which comprises treating a continuously fed charge ofmaterial containing aluminum and silicon and oxygen with a continuousfeed of chlorin and a reducing agent to form aluminum chlorid, silicontetrachlorid and a compound be tween said reducing agent and the oxygen,and continuously submitting the gaseous mixture thus formed to anatmosphere which will condense the aluminum chlorid but not the silicontetrachlorid of said compound.

13. The process of separating aluminum chlorid and silicon tetra-chloridwhich comprises submitting the mixture to an atmosphere which willcondense one but not the other under such conditions as topreventmoisture affecting them.

In witness whereof, I hereunto subscribe myname this {ith day of JanuaryA. D. 1915.

VICTOR M. WEAVER.

Witnesses:

EDWARD J. DUNLAP, NOAH S. HEISEY.

